A heavy truck operating condition vibration path identification method

Abstract

The application discloses a heavy truck operating condition vibration path identification method, comprising the following steps: S1, synchronously collecting response signals of multiple reference points and a response signal of a target point under the operating condition of a heavy truck; S2, calculating average contribution ratios and average coherence coefficients of each reference point to the target point in a preset target frequency band through operating condition transmission path analysis; S3, performing operating deformation mode analysis on the heavy truck to obtain a structural operating deformation mode in the preset target frequency band; S4, performing spatial consistency comparison and verification on a structural region corresponding to a high-contribution path screened out in step S2 and a large-deformation region of the structural operating deformation mode obtained in step S3; and S5, constructing a path comprehensive importance index according to the average contribution ratios, the average coherence coefficients and the spatial consistency comparison and verification result, and determining a dominant vibration transmission path according to path comprehensive importance index sorting. The application can improve the accuracy and efficiency of heavy truck vibration path identification.

Description

Technical Field

[0001] This invention relates to the field of heavy-duty truck vibration reduction technology, and in particular to a method for identifying vibration paths during heavy-duty truck operation. Background Technology

[0002] In related technologies, traditional transfer path analysis (TPA) requires disassembling components to measure a large number of frequency response functions, resulting in high testing costs and long cycles. Furthermore, it is difficult to apply directly to the actual operating conditions of the entire vehicle. For the vibration characteristics of heavy-duty trucks with multi-source excitation and multi-path coupling, existing methods often neglect the nonlinear coupling effects and operating condition dependencies between paths when identifying the dominant path, leading to inaccurate ranking of path contributions. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a method for identifying vibration paths under heavy-duty truck operating conditions, which can solve the technical problems of insufficient accuracy and low efficiency in identifying vibration paths of heavy-duty trucks in the prior art.

[0004] A method for identifying vibration paths during heavy-duty truck operation according to the present invention includes the following steps: S1. Under the operating conditions of heavy trucks, the response signals of multiple reference points and the response signal of the target point are collected simultaneously; S2. Based on the response signals of the reference point and the target point, calculate the average contribution ratio and average coherence coefficient of each reference point to the target point within the preset target frequency band through operational condition transmission path analysis. S3. Based on the response signals collected in the same batch, perform operational deformation mode analysis on the heavy truck to obtain the structural operational deformation mode within the preset target frequency band; S4. Verify the spatial consistency between the structural regions corresponding to the high contribution paths selected in step S2 and the large deformation regions of the structural operation deformation mode obtained in step S3. S5. Based on the verification results of the average contribution ratio, average coherence coefficient, and spatial consistency comparison, construct a path comprehensive importance index, and determine the dominant vibration transmission path according to the ranking of the path comprehensive importance index.

[0005] Optionally, in step S2, the formula for calculating the average contribution ratio is: in, The average contribution ratio of the nth reference point within the target frequency band Ω. Let Y(ω) be the cross-spectral density function between the target point and the nth reference point, Y(ω) be the self-spectral density function of the target point, and Ω be the target frequency band.

[0006] Optionally, in step S2, the formula for calculating the average coherence coefficient is: in, Let n be the coherence function between the reference point and the target point. Let Ω be the coherence function between the nth reference point and the target point, and Ω be the bandwidth of the frequency band Ω. The average coherence coefficient is used to filter noise and weakly correlated paths. If the value is below the preset threshold, the corresponding path is determined to be an invalid path.

[0007] Optionally, in step S4, the specific criterion for determining the spatial consistency comparison verification is as follows: If the physical connection area or structural component corresponding to the high contribution path selected by the operational condition transmission path analysis has a spatial overlap with the area where the amplitude peak is located in the operational deformation mode analysis, the path is determined to be a critical transmission path. If the two do not coincide in spatial location, the path is determined to be a pseudo path, and reference points are re-selected.

[0008] Optionally, in step S5, the path comprehensive importance index The calculation formula is: in, and These are the weighting coefficients. To obtain the consistency verification factor for running the deformation mode analysis; when the confidence level of the determined path is high in step S4. Set to 1; when a false path risk is detected, The penalty coefficient is 0 or less than 1.

[0009] Optionally, the operating conditions include road surface periodic excitation conditions or powertrain torque excitation conditions; when it is a road surface periodic excitation condition, the preset target frequency band is the overlapping frequency band of the unsprung running mode frequency and the local structural bending mode frequency, and the identification objects of the dominant vibration transmission path include the vertical transmission links from the rear axle unsprung system to the chassis, from the chassis to the front bulkhead, and from the front bulkhead to the instrument panel; when it is a powertrain torque excitation condition, the preset target frequency band is the overlapping frequency band of the engine's main order excitation frequency and the powertrain torsional resonance frequency band, and the identification objects of the dominant vibration transmission path include the longitudinal transmission links from the powertrain to the intermediate support of the driveshaft, from the intermediate support of the driveshaft to the chassis, and from the chassis to the cab suspension.

[0010] Optionally, in step S1, the location of the reference points covers potential vibration sources, key transmission nodes, and locally weak structures, and the target points are human-sensory sensitive points such as driver's seat rails, steering wheels, or dashboards; the types of signals collected include acceleration signals, rotational speed signals, and torque signals.

[0011] This invention offers at least the following advantages: By introducing average coherence coefficient and spatial consistency comparison verification, it effectively filters out noise and weakly correlated paths, avoids pseudo-path interference, and significantly improves the accuracy and robustness of transmission path identification. Simultaneously, based on the comprehensive importance index of paths, it can quantify the contribution weight of each path under specific working conditions, providing clear priorities for subsequent structural optimization and vibration reduction design, thereby shortening the development cycle and reducing the cost of experimental and simulation iterations. This method combines frequency domain analysis with spatial verification, ensuring both the clarity of the physical mechanism and the convenience of engineering applications, providing a reliable technical path for the rapid diagnosis and precise management of vibration transmission problems in complex structures.

[0012] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a flowchart of a method for identifying vibration paths in the operating conditions of heavy-duty trucks according to an embodiment of the present invention. Detailed Implementation

[0015] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0016] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0017] Below, refer to Figure 1 This invention describes a method for identifying vibration paths during heavy-duty truck operation, comprising the following steps: S1. Under the operating conditions of heavy trucks, the response signals of multiple reference points and the response signal of the target point are collected simultaneously; S2. Based on the response signals of the reference point and the target point, calculate the average contribution ratio and average coherence coefficient of each reference point to the target point within the preset target frequency band through operational condition transmission path analysis. S3. Based on the response signals collected in the same batch, perform operational deformation mode analysis on the heavy truck to obtain the structural operational deformation mode within the preset target frequency band; S4. Verify the spatial consistency between the structural regions corresponding to the high contribution paths selected in step S2 and the large deformation regions of the structural operation deformation mode obtained in step S3. S5. Based on the verification results of the average contribution ratio, average coherence coefficient, and spatial consistency comparison, construct a path comprehensive importance index, and determine the dominant vibration transmission path according to the ranking of the path comprehensive importance index.

[0018] In step S1, the response signals of the multiple reference points include, but are not limited to, acceleration or force response signals at key locations such as engine mounts, gearbox mounts, cab mounts, and axle connection points.

[0019] In some embodiments, in step S2, the formula for calculating the average contribution ratio is: in, The average contribution ratio of the nth reference point within the target frequency band Ω. Let Y(ω) be the cross-spectral density function between the target point and the nth reference point, Y(ω) be the self-spectral density function of the target point, and Ω be the target frequency band.

[0020] In some embodiments, the formula for calculating the average coherence coefficient in step S2 is: in, Let n be the coherence function between the reference point and the target point. Let Ω be the coherence function between the nth reference point and the target point, and Ω be the bandwidth of the frequency band Ω. The average coherence coefficient is used to filter noise and weakly correlated paths. If the value is below the preset threshold, the corresponding path is determined to be an invalid path.

[0021] In some embodiments, the specific criterion for determining the spatial consistency comparison verification in step S4 is as follows: If the physical connection area or structural component corresponding to the high contribution path selected by the operational condition transmission path analysis has a spatial overlap with the area where the amplitude peak is located in the operational deformation mode analysis, the path is determined to be a critical transmission path. If the two do not coincide in spatial location, the path is determined to be a pseudo path, and reference points are re-selected.

[0022] In some embodiments, in step S5, the path comprehensive importance index The calculation formula is: in, and These are the weighting coefficients. To obtain the consistency verification factor for running the deformation mode analysis; when the confidence level of the determined path is high in step S4. Set to 1; when a false path risk is detected, The penalty coefficient is 0 or less than 1.

[0023] In some embodiments, the operating conditions include road periodic excitation conditions or powertrain torque excitation conditions; when it is a road periodic excitation condition, the preset target frequency band is the overlapping frequency band of the unsprung running mode frequency and the local structural bending mode frequency, and the identification objects of the dominant vibration transmission path include the vertical transmission links from the rear axle unsprung system to the chassis, from the chassis to the front bulkhead, and from the front bulkhead to the instrument panel; when it is a powertrain torque excitation condition, the preset target frequency band is the overlapping frequency band of the engine main order excitation frequency and the powertrain torsional resonance frequency band, and the identification objects of the dominant vibration transmission path include the longitudinal transmission links from the powertrain to the driveshaft intermediate support, from the driveshaft intermediate support to the chassis, and from the chassis to the cab suspension.

[0024] In some embodiments, in step S1, the location of the reference point covers potential vibration sources, key transmission nodes, and locally weak structures, and the target point is a human-sensory sensitive point such as the driver's seat rail, steering wheel, or dashboard; the types of signals collected include acceleration signals, rotational speed signals, and torque signals.

[0025] The following is a specific embodiment to illustrate the implementation process and effects of the method described in this invention.

[0026] Two representative mass-produced heavy-duty truck platforms were selected for analysis, designated Heavy-Duty Truck I (HDT-I) and Heavy-Duty Truck II (HDT-II). When HDT-I travels at low to medium speeds on roads with periodically uneven geometry, noticeable low-frequency vibrations occur in the cab, with the vibration energy concentrated in a narrow frequency band. In contrast, HDT-II exhibits continuous longitudinal vibrations within a specific engine speed range during fully loaded acceleration and gear shifting. The vibration frequency shows no significant correlation with vehicle speed changes, exhibiting typical characteristics of powertrain excitation.

[0027] To address the vibration issue of HDT-I, reference and target points were first established at the unsprung components of the rear suspension, the front suspension system, chassis nodes, the front bulkhead, and the steering wheel to collect acceleration signals under road surface excitation. Simultaneously, vehicle speed and wheel speed pulse signals were collected to synchronize time-domain data. Based on the spectral analysis in step S1, significant energy concentration was observed in the 12–16 Hz frequency band at 30 km / h. This frequency band highly matches the 13.9 Hz excitation frequency calculated from the geometric period of the road surface passing through continuous speed bumps, and precisely covers the unsprung vibration mode frequency (approximately 15 Hz).

[0028] Subsequently, according to step S2, the average contribution ratio and average coherence coefficient of each reference point to the target point within the preset target frequency band are calculated through operational condition transmission path analysis. Paths with a contribution ratio greater than 20% and a coherence coefficient greater than 0.6 are selected as candidates. Thus, three high-contribution paths are initially identified: rear axle to chassis, chassis to front bulkhead, and front bulkhead to instrument panel.

[0029] According to step S3, the operational deformation mode analysis of the heavy truck is performed to obtain the structural operational deformation mode within the target frequency band.

[0030] According to step S4, the structural region corresponding to the high contribution path selected in step S2 is compared and verified with the large deformation region of the structural operation deformation mode obtained in step S3. It is confirmed that the instrument panel region has significant bending and torsional coupling deformation in the 12–16 Hz frequency band, and the deformation mode is highly consistent with the vibration transmission direction of the chassis to front bulkhead path.

[0031] Within the 12–16 Hz frequency band, the vertical transmission path from the rear axle unsprung system to the chassis longitudinal beams contributed 38% and had a coherence coefficient of 0.82, thus being identified as the dominant path. Further analysis revealed that when the vibration energy from this path was transmitted to the front bulkhead region via the chassis longitudinal beams, the front bulkhead exhibited significant out-of-plane bending deformation within the 12–16 Hz frequency band. The ODS mode shape showed that the amplitude was largest in the central region and was highly correlated with the steering wheel vibration response. Ultimately, the vibration transmission mechanism of this dominant path was confirmed as follows: the rear axle unsprung vibration excitation was transmitted to the front bulkhead via the chassis longitudinal beams, exciting local bending modes in the front bulkhead, thereby amplifying the vibration response at the steering wheel.

[0032] Based on step S5, the overall importance index ranking results show that the rear axle → chassis longitudinal beam → front bulkhead → steering wheel path has the highest overall importance index, reaching 0.87, significantly higher than other candidate paths. Therefore, the root cause of the HDT-I's vibration problem is identified as the unsprung rear axle vibration being transmitted to the front bulkhead via the chassis longitudinal beam, exciting the local bending mode of the front bulkhead, and thus amplifying the steering wheel vibration response. To address this path, a local reinforcing rib is added at the connection between the chassis longitudinal beam and the front bulkhead, while simultaneously optimizing the connection stiffness between the front bulkhead and the steering wheel bracket. This increases the first-order bending mode frequency of the front bulkhead from 13.5 Hz to over 18 Hz, effectively avoiding the dominant frequency band of road surface excitation. This improves the steering wheel vibration problem of the HDT-I under periodic road surface excitation.

[0033] Regarding the vibration issue of the HDT-II, following step S1, the acceleration of the seat rails in the HDT-II was first tested under full load conditions within the engine speed range of 1100–1300 rpm. The results showed that its vibration characteristics were distinctly different from the HDT-I: the seat rails exhibited a sharp peak near 1120 rpm, while the benchmark vehicle showed a smooth curve with no significant fluctuations at that speed. Further torsional vibration testing of the powertrain revealed a significant torsional vibration peak on the transmission side near 1120 rpm, and this torsional vibration frequency was completely consistent with the vibration frequency of the seat rails.

[0034] Subsequently, according to step S2, a contribution analysis was performed on the vibration transmission path from the powertrain to the seat, identifying the dominant path consisting of the driveshaft center support, chassis longitudinal beams, cab front suspension, and seat rails. At 1120 rpm, this path contributed 45% with a coherence coefficient of 0.79, and was identified as the critical transmission path. Another secondary path, from the driveshaft center support to the seat rails, contributed 22% with a coherence coefficient of 0.65 and was identified as an auxiliary path.

[0035] According to step S3, the operational deformation mode analysis of the heavy truck is performed to obtain the structural operational deformation mode within the target frequency band.

[0036] According to step S4, the structural region corresponding to the high contribution path selected in step S2 is compared and verified with the large deformation region of the structural deformation mode obtained in step S3. The results show that at 1120 rpm, the central support of the drive shaft exhibits obvious resonance deformation in the vertical direction, and its peak amplitude is highly consistent with the vibration response of the seat guide rail.

[0037] According to step S5, the overall importance index ranking result of the path is as follows: the overall importance index of the path driveshaft center support → chassis longitudinal beam → cab front suspension → seat guide rail is the highest, reaching 0.83, which is much higher than other candidate paths. Therefore, the root cause of the vibration problem of HDT-II is identified as the resonance of the driveshaft center support at 1120 rpm, which causes the vibration to be transmitted to the seat guide rail through the chassis longitudinal beam and the cab front suspension, resulting in the cab swaying back and forth. To address this problem, it is proposed to add a damping bushing at the connection between the driveshaft center support bracket and the chassis longitudinal beam, and to optimize the local stiffness of the support bracket, shifting the resonance frequency of the center support from the excitation frequency corresponding to 1120 rpm to outside the operating speed range.

[0038] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0039] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for identifying vibration paths during heavy-duty truck operation, characterized in that, Includes the following steps: S1. Under the operating conditions of heavy trucks, synchronously collect response signals from multiple reference points and the target point; S2. Based on the response signals of the reference point and the target point, calculate the average contribution ratio and average coherence coefficient of each reference point to the target point within the preset target frequency band through operational condition transmission path analysis. S3. Based on the response signals collected in the same batch, perform operational deformation mode analysis on the heavy truck to obtain the structural operational deformation mode within the preset target frequency band; S4. Verify the spatial consistency between the structural regions corresponding to the high contribution paths selected in step S2 and the large deformation regions of the structural operation deformation mode obtained in step S3. S5. Based on the verification results of the average contribution ratio, average coherence coefficient, and spatial consistency comparison, construct a path comprehensive importance index, and determine the dominant vibration transmission path according to the ranking of the path comprehensive importance index.

2. The method for identifying vibration paths during heavy-duty truck operation as described in claim 1, characterized in that, In step S2, the formula for calculating the average contribution ratio is: in, The average contribution ratio of the nth reference point within the target frequency band Ω. Let Y(ω) be the cross-spectral density function between the target point and the nth reference point, Y(ω) be the self-spectral density function of the target point, and Ω be the target frequency band.

3. The method for identifying vibration paths during heavy-duty truck operation as described in claim 1, characterized in that, In step S2, the formula for calculating the average coherence coefficient is: in, Let n be the coherence function between the reference point and the target point. Let Ω be the coherence function between the nth reference point and the target point, and Ω be the bandwidth of the frequency band Ω. The average coherence coefficient is used to filter noise and weakly correlated paths. If the value is below the preset threshold, the corresponding path is determined to be an invalid path.

4. The method for identifying vibration paths during heavy-duty truck operation as described in claim 1, characterized in that, In step S4, the specific judgment criteria for the spatial consistency comparison verification are as follows: If the physical connection area or structural component corresponding to the high contribution path selected by the operational condition transmission path analysis has a spatial overlap with the area where the amplitude peak is located in the operational deformation mode analysis, the path is determined to be a critical transmission path. If the two do not coincide in spatial location, the path is determined to be a pseudo path, and reference points are re-selected.

5. The method for identifying vibration paths during heavy-duty truck operation as described in claim 1, characterized in that, In step S5, the path comprehensive importance index The calculation formula is: in, and These are the weighting coefficients. To obtain the consistency verification factor for running the deformation mode analysis; when the confidence level of the determined path is high in step S4. Set to 1; when a false path risk is detected, The penalty coefficient is 0 or less than 1.

6. The method for identifying vibration paths during heavy-duty truck operation according to claim 1, characterized in that, The operating conditions include road periodic excitation conditions or powertrain torque excitation conditions; when it is a road periodic excitation condition, the preset target frequency band is the overlapping frequency band of the unsprung running mode frequency and the local structural bending mode frequency, and the identification objects of the dominant vibration transmission path include the vertical transmission links from the rear axle unsprung system to the chassis, from the chassis to the front bulkhead, and from the front bulkhead to the instrument panel. When the powertrain torque excitation condition is applied, the preset target frequency band is the overlapping frequency band of the engine's main excitation frequency and the powertrain torsional resonance frequency band. The identification objects of the dominant vibration transmission path include the longitudinal transmission links from the powertrain to the intermediate support of the drive shaft, from the intermediate support of the drive shaft to the chassis, and from the chassis to the cab suspension.

7. The method for identifying vibration paths during heavy-duty truck operation as described in claim 1, characterized in that, In step S1, the reference points are arranged to cover potential vibration sources, key transmission nodes, and locally weak structures. The target points are human-sensory sensitive points such as driver's seat rails, steering wheels, or dashboards. The types of signals collected include acceleration signals, rotational speed signals, and torque signals.

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